>>16681006fire is very very important against certain pervasive targets.
>>16681042psuedo stats in a very good distribution and an ability which boosts it's special defense make it good. typing isn't the only thing that determines how good a pokemon is. when thinking about type you have to ignore these other things.
although when thinking about balance you could easily skew the type chart by using other factors. grass is a very weak type but it has access to very strong moves and is immune to those same moves.
ice could be made a lot better without changing the type matchups. if they just created some great ice type moves and gave them exclusive distribution it would make ice pokemon better.
if they invented an ice type shell smash that removed entry hazards and was exclusive to ice type pokemon you would see a lot more ice type pokemon.